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算法：
原图像：颜色值color=（R，G，B）
新图像：
RNew=255-R
GNew=255-G
BNew=255-B
color=（RNew，GNew，BNew）
'逆反 Private Sub btnInversion_Click(sender As Object, e As EventArgs) Handles btnInversion.Click Dim pSourceColor As Color Dim pDestColor As Color Dim destImg As New Bitmap(sourceImg.Width, sourceImg.Height) Dim R, G, B As Integer For i As Integer = 0 To sourceImg.Width - 1 For j As Integer = 0 To sourceImg.Height - 1 pSourceColor = sourceImg.GetPixel(i, j) R = pSourceColor.R G = pSourceColor.G B = pSourceColor.B R = 255 - R G = 255 - G B = 255 - B pDestColor = Color.FromArgb(R, G, B) destImg.SetPixel(i, j, pDestColor) Next Next picDest.Image = destImg End Sub
处理结果如下：
4、曝光
算法：先定义一个阈值，通常取得是128
原图像：颜色值color=（R，G，B）
新图像：
如果R<阈值，那么RNew=255-R
如果G<阈值，那么GNew=255-G
如果B<阈值，那么BNew=255-B
color=（RNew，GNew，BNew）
'曝光 Private Sub btnExposure_Click(sender As Object, e As EventArgs) Handles btnExposure.Click Dim pSourceColor As Color Dim pDestColor As Color Dim destImg As New Bitmap(sourceImg.Width, sourceImg.Height) Dim R, G, B As Integer For i As Integer = 0 To sourceImg.Width - 1 For j As Integer = 0 To sourceImg.Height - 1 pSourceColor = sourceImg.GetPixel(i, j) R = pSourceColor.R G = pSourceColor.G B = pSourceColor.B If R < 128 Then R = 255 - R If G < 128 Then G = 255 - G If B < 128 Then B = 255 - B pDestColor = Color.FromArgb(R, G, B) destImg.SetPixel(i, j, pDestColor) Next Next picDest.Image = destImg End Sub
处理结果如下：
由于.net平台下C#和vb.NET很相似，本文也可以为C#爱好者提供参考。
学习更多vb.net知识，请参看 vb.net 教程 目录
